Answer:
0.087 moles of water
Explanation:
Given data:
Number of molecules of water = 5.24×10²² molecules
Number of moles of water = ?
Solution:
The given problem will solve by using Avogadro number.
1 mole = 6.022 × 10²³ molecules of water
5.24×10²² molecules × 1 mol / 6.022 × 10²³ molecules
0.87×10⁻¹ mol
0.087 mol
Avogadro number:
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance. The number 6.022 × 10²³ is called Avogadro number.
Answer:
See Explanation
Explanation:
1) Let us recall that;
Mass number = number of protons + number of neutrons
Where;
Number of protons = ?
Number of neutrons =20
Mass number =39
Number of protons = mass number - number of neutrons
Mass of protons =39 - 20= 19 protons
2) Atomic number = 13
Number of neutrons =14
Then the mass number =13 +14 =27
The symbol of the element is 27X13
The number of protons= the number of electrons =13
The atomic number is the same as the proton number =13
CaCl2(aq) + K2CO3(aq) → 2 KCl(aq) + CaCO3(aq)
1.12 g
2.23 g
0.896 g
4.47 g
1.12 g
Hope it helps :)
Answer:
See explanation
Explanation:
According to the Bohr model of the atom, electrons are found in energy levels. Energy is absorbed or emitted when an electron moves from one energy level to another.
During flame test, electrons absorb energy and move to higher energy levels; they quickly return to ground state and emit the energy previously absorbed as a photon of light. This is seen as the colour imparted to the flame by the metal.
The emission spectrum tells us about the range of wavelengths emitted by an atom or compound when it is excited. At an atomic level, the electrons are moved to higher energy levels and as they return to ground state, they emit the various wavelengths that comprise the emission spectrum of any particular substance.
25.0 g.....................................................
